<SEC-DOCUMENT>0001225208-17-005643.txt : 20170306
<SEC-HEADER>0001225208-17-005643.hdr.sgml : 20170306
<ACCEPTANCE-DATETIME>20170306174110
ACCESSION NUMBER:		0001225208-17-005643
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170302
FILED AS OF DATE:		20170306
DATE AS OF CHANGE:		20170306

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ON SEMICONDUCTOR CORP
		CENTRAL INDEX KEY:			0001097864
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				363840979
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		5005 EAST MCDOWELL ROAD
		CITY:			PHOENIX
		STATE:			AZ
		ZIP:			85008
		BUSINESS PHONE:		6022446600

	MAIL ADDRESS:	
		STREET 1:		5005 EAST MCDOWELL ROAD
		CITY:			PHOENIX
		STATE:			AZ
		ZIP:			85008

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SCG HOLDING CORP
		DATE OF NAME CHANGE:	19991027

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hall William
		CENTRAL INDEX KEY:			0001364183

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30419
		FILM NUMBER:		17669010

	MAIL ADDRESS:	
		STREET 1:		ON SEMICONDUCTOR C/O M. ROGERS  M/D A700
		STREET 2:		5005 EAST MCDOWELL ROAD
		CITY:			PHOENIX
		STATE:			AZ
		ZIP:			85008
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-03-02</periodOfReport>

    <issuer>
        <issuerCik>0001097864</issuerCik>
        <issuerName>ON SEMICONDUCTOR CORP</issuerName>
        <issuerTradingSymbol>ON</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001364183</rptOwnerCik>
            <rptOwnerName>Hall William</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5005 EAST MCDOWELL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PHOENIX</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85008</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>EVP &amp; GM, Pwr Sol Grp</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common</value>
            </securityTitle>
            <transactionDate>
                <value>2017-03-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4301.0000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.1600</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>377956.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common</value>
            </securityTitle>
            <transactionDate>
                <value>2017-03-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4628.0000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.2100</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>373328.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common</value>
            </securityTitle>
            <transactionDate>
                <value>2017-03-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9255.0000</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.2100</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>364073.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This disposition transaction represents shares withheld by the Issuer in connection with the March 2, 2015 restricted stock units award to the Reporting Person under the Issuer's Amended and Restated Stock Incentive Plan.  On March 2, 2017, certain of these units vested.  These shares were withheld to satisfy the Reporting Person's tax withholding obligations.  The Issuer will pay these taxes on behalf of the Reporting Person.</footnote>
        <footnote id="F2">This disposition transaction represents shares withheld by the Issuer in connection with the March 3, 2014 restricted stock units award to the Reporting Person under the Issuer's Amended and Restated Stock Incentive Plan.  On March 3, 2017, certain of these units vested.  These shares were withheld to satisfy the Reporting Person's tax withholding obligations.  The Issuer will pay these taxes on behalf of the Reporting Person.</footnote>
        <footnote id="F3">This disposition transaction represents shares withheld by the Issuer in connection with the Reporting Person's 2014 Performance Based Restricted Stock Units award and related award agreements.  On March 3, 2017, certain of these units vested.  These shares were withheld to satisfy the Reporting Person's tax withholding obligations.  The Issuer will pay these taxes on behalf of the Reporting Person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Mark N. Rogers, Attorney-in-Fact</signatureName>
        <signatureDate>2017-03-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
